In a rotary printing press, a material web is guided through a plurality of printing units where the web may be printed on both sides and in many colors. It is then guided into a dryer, for example, a hot air dryer, in order to dry it. The web is then transported over cooling rollers of a cooling stand in order to cool down the web heated by the dryer. Thereafter, the web can be cut and folded into signatures in a folder and the signatures transported onward for further processing in, for example, a distribution system.
U.S. Pat. No. 5,049,798 discloses a control system for a printing press which is not reconfigurable and requires a master reference (FIG. 1) that is connected to a single preselected print unit. The preselected print unit acts as the master and provides control signals to each of the remaining print units and folders.
U.S. Pat. No. 5,615,609 discloses that a significant aspect of multi-color printing is the importance of achieving and maintaining precise print registration among each of the multiple printing cylinders as the printing operation is conducted. This precision is needed to obtain proper alignment of the multi-color ink patterns on the paper material and avoid overlap or smearing of the colored ink patterns. However, the system disclosed therein is not reconfigurable.
U.S. Pat. No. 5,894,802 also discloses a control system for a printing press which is not reconfigurable and requires an isolated position reference unit (FIGS. 3 and 4) that outputs a position reference signal to each of a plurality of print units based on a signal from a master reference source 32, with each print unit having a separate regulator (e.g., regulator 720) for controlling the speed of the drive motors (e.g., motor 3).
U.S. Pat. No. 6,701,836 discloses that for a drive system of a printing machine with drives for each printing stage and printing ink, respectively, it is necessary to keep the drive motors of the various drives synchronized in order to be able to realize good printed results. The drive system disclosed requires drive control units at each print unit and a separate master control unit which communicates with and provides control signals to each drive control unit.
U.S. Pat. Nos. 5,615,609, 5,894,802 and 6,701,836 are hereby incorporated by reference herein.